Downhole valves have been used to provide selective access from different strata into a well. Typically these valves employ a sliding sleeve to selectively align or mis-align openings on an inner sliding sleeve mounted concentrically with a housing. The sliding sleeve can have grooves or recesses near its end for engagement by a tool to slide the sleeve in one direction or another. Typically the tool to operate the sliding sleeve is delivered on coiled tubing or wireline, however, rigid tubing could also be used.
Many applications in deviated wellbores, particularly those with long horizontal sections, present unique difficulties to the traditional methods of operating sliding sleeve valves with tools delivered on coiled tubing or wireline. Other applications, such as junctions in multi-lateral systems have such small inside diameters so as to make operation of the sleeve using coiled tubing or wireline, virtually impossible.
One solution to this problem of lack of access for traditional tools to shift the sleeve has been to provide a local source of power, such as a battery, and use it to power the sleeve between the open and closed positions. However, there are still reliability issues with using battery power and should the valve fail to close, there is no backup way to get access to it to get it to close.
The need to use valves in applications where traditional type of access is not available, has spurred the need for the present invention. In seeking a more reliable way to operate a valve that, in effect, cannot be mechanically accessed, the valve of the present invention has been developed. The valve features, in a preferred embodiment, an annular passage lined with a material that is sensitive to some fluids but not to others. It can remain open until contacted by a fluid that makes the liner swell. The swelling closes off the flow path through the valve body to allow subsequent operations to take place. This valve type has particular application to screened main bores used in conjunction with open laterals. In such applications, high mud flow rates are experienced during completion operations making it desirable to bypass screens in the main bore completion. However, when production of hydrocarbons begins, it is desirable to close the bypass for the screens and direct production of hydrocarbons through such screens. The valve of the present invention can do this. Exposure to produced hydrocarbons can result in sufficient swelling to make the valve close. When this happens, the produced fluid can be directed to flow through a screen on the way to the surface. These and other advantages of the present invention will become apparent to those skilled in the art from a review of the description of the preferred embodiment and the drawings and the claims that appear below.